The time taken for 90% of a first order reaction to complete is approximately

Options

A. 1.1 times that of half life
B. 2.2 times that of half life
C. 3.3 times that of half life
D. 4.4 times that of half life

Answer

C

Explanation

( C) `t_(90%)= (2.303)/(k) "log" (a)/(a-0.9a) `
`= (2.303)/(k) "log" 10 = (2.303)/(k)`
`t_(1//2)= (2.303)/(k) "log" (a)/(a-0.5a)`
`= (2.303)/(k ) "log" 2`
`t_(1//2) = (2.303xx0.3010)/(k) `
`:. (T_(90%))/(t_(1//2))= (1)/(0.3010) 3.3`
`:. t_(90%) = 3.3t_(1//2) `